Braking Force

How do i, ie what is the forumla, to calculate braking distance,
for example; If i had a question says, a 600kg car, traveling 30ms-1, and comes to rest in 10s after braking. What is the average braking force?

How do I, ie what is the forumla, to calculate braking distance,
for example; If i had a question says, a 1500kg car, traveling 30ms-1, and comes to rest over a distance 40m after braking. What is the average braking force?

[How do i, ie what is the forumla, to calculate the force act on the particle eg; A particle of mass 0.01 kg is moving with avelocity 10 ms-1 on a smooth surface. A force 6 N acts on the particles such that its velocity increases to 15 m s-1. How would i go about calculating it?